Helmet with custom foam liner and removable / replaceable layers of crushable energy absorption material

ABSTRACT

Multi-layered helmets deformably absorb an impact to a wearer that are provided with a rigid outer shell, a plurality of collapsible members configured to be permanently deformable to absorb energy in response to an applied force, and a flexible inner liner. The collapsible members are individually attachable to and removable from the inner surface of the rigid outer shell and to the flexible inner liner in a manner allowing individual replacement of a collapsible member upon being permanently deformed. The inside of the flexible inner liner is configured to face the head of a wearer.

CROSS REFERENCE TO RELATED APPLICATION

This application claims the benefit of priority from U.S. Provisional Application No. 61/762,939, filed Feb. 10, 2013, and entitled HELMET WITH CUSTOM FOAM LINER AND REMOVABLE LAYER OF CRUSHABLE ENERGY ABSORPTION MATERIAL, the disclosure of which is incorporated, in its entirety, by this reference.

TECHNICAL FIELD

The following relates generally to protective helmets and specifically to customized protective helmets having replaceable collapsible parts.

BACKGROUND

Protective helmets are used in a wide range of industrial, military, and recreational activities, including construction, vehicle safety, sports, motorcycling, and other applications. Traditionally, these helmets provide a protective barrier against the application of forces to the head that are likely to cause head injuries or concussion of the brain. This is done by a substantially rigid foam layer positioned to portions of the wearer's head that are prone to being impacted. This foam layer is strapped to the head, usually by chin straps. Under normal use, the foam layer is designed to rigidly maintain its shape, but when the helmet is impacted by a great enough force, the rigid foam crushes or collapses and absorbs at least a portion of the energy, thereby reducing the overall impulse absorbed by the wearer.

In some cases, the foam layer is externally covered by a rigid plastic, composite, or other durable material. This outer layer may be stiff enough to prevent the foam from incidental damage occurring from normal use while still being flexible enough to deform into the foam layer upon a serious impact. The foam layer may also include inner pads positioned between the foam layer and the user's head to improve comfort and to absorb minor movements of the helmet relative to the wearer.

Existing helmet technology does not generally provide enough energy absorption for the wearer's head. A rigid shell on the outer area of the helmet is typically designed to maintain its integrity even under very high impacts, and therefore the helmet as a whole does not absorb enough energy to protect the wearer. The inner foam protection is also designed in the same way. It is designed to keep its integrity on softer and medium impact Forces. This does not allow for as much energy absorption because the material just doesn't crush or collapse to the extent of the proposed foam protection layers. This is usually done to protect the helmet and allow it to be reusable, since failure of the shell or the foam layer within the shell is catastrophic, unrepairable damage to the helmet.

Generally speaking, these protective helmets are only designed to sustain one major impact. When the foam layer collapses, it breaks and loses a significant amount of its ability to absorb energy a second time, and the entire helmet must be discarded. This leads to excessive waste and can be unduly costly to replace, particularly when a helmet is cosmetically or functionally customized. Other helmets may be able to withstand repeated impacts, but the materials used in their construction are expensive and, in some cases, less effective in a crash.

Additionally, protective helmets are often found in a number of discrete sizes that are supposed to fit a general cross-section of the public. While a specific helmet may technically be wearable, too frequently it may allow an undesirable amount of relative movement between the head and the inner surfaces of the helmet. Some helmets provide soft cushioning that forms to each wearer's head, but this may reduce safety due to loosening the fit of the helmet, and may lead to the helmets feeling tighter or looser than is comfortable for some wearers.

Therefore, improvements in protective helmets are desirable.

SUMMARY

According to at least one embodiment, a multi-layered helmet for deformably absorbing an impact to a wearer may be disclosed and provided herein. The multi-layered helmet may comprise a rigid outer shell having an inner surface, a plurality of collapsible members individually attachable to and removable from the inner surface of the rigid outer shell, wherein the plurality of collapsible members are individually replaceable upon being permanently deformed, and a flexible inner liner having an outer surface and an inner surface, the plurality of collapsible members being individually attachable to and removable from the outer surface of the inner liner, the inner surface of the flexible inner liner being configured to rest against the head of a wearer. The plurality of collapsible members may be permanently deformable in response to an applied force, wherein the deformation absorbs impact energy from the applied force. The multi-layered helmet may also include a chin strap configured to secure the helmet to the head of the wearer.

The helmet may also comprise a plurality of voids formed at least in part by spaces between the plurality of collapsible members, wherein the flexible inner liner comprises extension portions extending toward the rigid outer shell and fitting within the plurality of voids. The permanent deformation of at least one of the plurality of collapsible members may be a breakage or a snapping of the least one of the plurality of collapsible members. At least one of the plurality of collapsible members may be permanently deformed by a crushing or a folding of the at least one of the plurality of collapsible members.

The plurality of collapsible members may be removably attachable to the rigid outer shell and the flexible inner liner by hook and loop fasteners covering at least a portion of the inner surface of the rigid outer shell, the plurality of collapsible members, and the outer surface of the flexible inner liner. A first portion of the hook and loop fasteners may removably attach at least one of the plurality of collapsible members to the rigid outer shell and a second portion of the hook and loop fasteners may removably attach the at least one of the plurality of collapsible members to the flexible inner liner, wherein the first and second portions may have different attachment strengths.

The plurality of collapsible members of the helmet may be removably attachable to the rigid outer shell and the flexible inner liner by a plurality of snap-fit connectors extending between the rigid outer shell, the collapsible members, and/or the flexible inner liner. These snap-fit connectors may be pins having a shear breakage section configured to break in response to an applied shear force. The shear breakage section may be positioned to be subjected to an applied shear force when the collapsible members translate relative to the rigid outer shell or the flexible inner liner. The snap-fit connectors may be removably insertable into openings in the plurality of collapsible members.

The plurality of collapsible members may also be removably attachable to the rigid outer shell and the flexible inner liner by a releasable ridge-and-groove connector.

The flexible inner liner may have varying thickness when measured relative to the inner surface of the rigid outer shell.

A first portion of the plurality of collapsible members may have a different rigidity than a second portion of the plurality of collapsible members.

The collapsible members may collapse to permit rotational or translational movement of the flexible inner liner relative to the rigid outer shell. Similarly, the collapsible members may collapse to permit rotational or translational movement of the outer shell relative to the flexible inner liner.

In another aspect of the present disclosure, a method of manufacturing a multi-layered helmet for deformably absorbing an impact to a head of a wearer is provided. The method may include providing a rigid outer shell having an inner surface, attaching a plurality of collapsible members to the inner surface of the rigid outer shell, the collapsible members being permanently deformable to absorb impact energy in response to a force applied to the rigid outer shell and having inner surfaces, and attaching a flexible inner liner to the inner surfaces of the plurality of collapsible members.

Attaching the plurality of collapsible members and attaching the flexible liner may comprise removably attaching the plurality of collapsible members and removably attaching the flexible inner liner, respectively. Removably attaching the plurality of collapsible members may further comprise providing a plurality of pin inserts, forming a plurality of cavities in the plurality of collapsible members, the plurality of cavities being shaped to receive the pin inserts, and inserting the plurality of pin inserts into the plurality of cavities and into the rigid outer shell and flexible inner liner, the pin inserts removably attaching the plurality of collapsible members to the rigid outer shell and to the flexible inner liner. The plurality of collapsible members may be more securely removably attached to the rigid outer shell than to the flexible inner liner.

In another embodiment, the method may include shaping the flexible inner liner to conform to the inner surfaces of the plurality of collapsible members and to a surface of the head of the wearer, wherein the flexible inner liner may include expansion portions to fill a plurality of voids between the plurality of collapsible members and the head of the wearer. The flexible inner liner may be shaped by molding the flexible inner liner to the shape of the inner surfaces of the collapsible members or rigid outer surface. The flexible inner liner may also comprise compartments or cavities that will allow for containing or contain a liquid or semi-liquid foam material. This material may be chemically activated to allow a custom forming and fit. This configuration may provide a better custom fit to the contours of a wearer's head.

A first portion and a second portion of the plurality of collapsible members may be attached to the inner surface of the outer shell, and the first portion may have greater rigidity than the second portion of the plurality of collapsible members.

Upon permanent deformation of at least one of the plurality of collapsible members, the method may further comprise detaching the flexible inner liner from the inner surfaces of the plurality of collapsible members, detaching a consumed first collapsible member from the inner surface of the rigid outer shell, wherein the consumed first collapsible member is individually detachable relative to the plurality of collapsible members, replacing the consumed first collapsible member with a second collapsible member, the second collapsible member having equivalent shape to the consumed first collapsible member, and reattaching the flexible inner liner to the inner surfaces of the plurality of collapsible members.

In another aspect of the present disclosure, a method of manufacturing a custom multi-layered helmet may comprise providing a rigid outer shell having an inner surface, the inner surface of the rigid outer shell being attached to a rigid collapsible pad having an inner surface, positioning a moldable liner blank adjacent to the inner surface of the rigid collapsible pad and adjacent to a surface of a head of a wearer, the liner blank contacting the inner surface of the rigid collapsible pad and the surface of the head simultaneously, molding the liner blank to a shape defined by the inner surface of the rigid collapsible pad and the surface of the head, stiffening the liner blank to retain the shape, and removably attaching the liner blank to the rigid outer shell or rigid collapsible pad. The molding process may be implemented using a capsule that is positioned around the head of the wearer and then inserting moldable material between the surfaces of the head and the surfaces of the collapsible pad members. The capsule may act as the outer shell of the helmet for the customization process. It may provide a boundary for the foam to push against, allowing the right amount of pressure to form to the head and also fill in to fit in the normal shell of the helmet.

The foregoing and other features, utilities and advantages of the invention will be apparent from the following more particular description of a preferred embodiment of the invention as illustrated in the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings and figures illustrate a number of exemplary embodiments and are part of the specification. Together with the present description, these drawings demonstrate and explain various principles of this disclosure. A further understanding of the nature and advantages of the present invention may be realized by reference to the following drawings. In the appended figures, similar components or features may have the same reference label.

FIG. 1 is a perspective view of a helmet according to an exemplary embodiment of the present disclosure.

FIG. 2 is a bottom view of the helmet of FIG. 1.

FIG. 3 is a side section view of a helmet according to another exemplary embodiment of the present disclosure.

FIG. 4 is an exploded side section view of the helmet of FIG. 3.

FIG. 5 is an illustration of a side section view of the helmet of FIG. 3 prior to final formation of a flexible inner layer.

FIG. 6 is a partial side section view illustration of one way multiple layers of a helmet may be attached to each other.

FIG. 7 is another partial side section view illustration of a way multiple layers of a helmet may be attached to each other.

FIG. 8 is another partial side section view illustration of a way multiple layers of a helmet may be attached to each other.

FIG. 9A shows a collapsible pad member attachable using tabs and pockets in an unsecured position.

FIG. 9B shows the collapsible pad member of FIG. 9A in a secured position.

FIGS. 10A-10K show cross-sectional exemplary profiles of collapsible pad members.

FIG. 11 shows a perspective view of an exemplary collapsible pad member profile.

FIGS. 12A-12M show photographs of exemplary test members for the profile shapes of FIGS. 10A-10K and 11.

FIGS. 13A-13B show another embodiment of a collapsible member configured to be attachable to an outer shell of a helmet of another embodiment of the present disclosure.

FIG. 14 illustrates another embodiment of a second impact layer of FIG. 13.

FIG. 15 illustrates another embodiment of a second impact layer of FIG. 13.

While the embodiments described herein are susceptible to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and will be described in detail herein. However, the exemplary embodiments described herein are not intended to be limited to the particular forms disclosed. Rather, the instant disclosure covers all modifications, equivalents, and alternatives falling within the scope of the appended claims.

DETAILED DESCRIPTION

In some aspects of the present disclosure, multi-layered helmets are described. Such helmets may include a rigid outer shell within which a plurality of collapsible pad members is attached. The collapsible pad members may be substantially rigid in order to absorb energy from a strong impulse applied to the outer shell. The collapsible pad members may be individually separate or separable from each other and may also be removable from the outer shell. This may allow the helmet to customize the flexibility and energy absorption characteristics of different regions within the helmet based on the types of pad members placed in each section of the helmet.

The function of the layers may be considered analogous to safety features used in competitive car racing (e.g., NASCAR), but instead of protecting a driver of a vehicle, the wearer of a helmet is protected from absorbing direct impacts and rotational impact energy. In competitive racing, the race tracks have a safety wall, the competitors' vehicles have specially-designed chassis, and the drivers use a custom-fitted seat and head harness system. The safety wall crushes or collapses on impact, then the car frame crushes, and the custom-fitted seat and harness keeps the driver stable and act as a final layer of protection as the wall and chassis absorb most of the impact energy.

In this analogy, the rigid outer shell of the helmet may be compared to the safety wall, the collapsible pad members may be likened to the chassis of the racing vehicle, and the flexible inner liner may be compared to the seat and harness in the vehicle. Thus, the outer shell of the helmet may be first to receive an impact in a collision with the helmet, then the collapsible pad members. These layers may absorb the majority of the energy of the impact while the flexible inner liner keeps the wearer's head stable and may absorb much less energy than it would without the outer layer and pad members.

Removable members may also allow the user to replace pad members that have permanently deformed, such as after an incident in which the pad members were crushed in an impact. The removable pad members may therefore permit the user to select sized pad members that fit more or less closely to his or her head, allowing for a more comfortable fit. For example, the stiffness and size of the pad members may be selected based on the anticipated activity of the wearer. A tighter, stiffer fit may be used for higher speed applications (e.g., off-road vehicle driving), and a looser, more comfortable fit may be used for slower speed applications (e.g., mountain biking). This may be beneficial because a comfortable fit encourages users to wear the helmet more consistently.

The helmet may additionally comprise a flexible inner layer or liner to be positioned between the collapsible members and the wearer's head. The flexible inner layer may be custom-molded to take the shape of the wearer's head on its inner surface and to take the shape of the various collapsible pad members on its outer surface. Thus, the flexible inner layer may be configured to closely conform to the surfaces of the head of the wearer. The flexible inner liner may fill or decrease the size of voids between the collapsible members to provide additional cushioning and to give the helmet a solid feel and improved warmth and protection. The shaped outer surface of the flexible inner layer may be attachable to the inner surfaces of the collapsible members, and in some embodiments, may be removably attachable thereto. The shaped outer surface of the flexible inner layer may thus be used to assist the user to properly position the collapsible members relative to the inner surfaces of the outer shell of the helmet. In some embodiments, the inner surface of the flexible inner layer may be shaped similar to generic surfaces of a wearer's head instead of being custom-molded. The inner surfaces of the liner may comprise a thin wicking fabric material within the form fitting, soft, pliable, memory elastic foam used in other parts of the flexible inner layer. The flexible inner layer may be designed to withstand multiple impacts and may therefore be a reusable base for the collapsible pad members and outer layer.

In another aspect of the present disclosure, methods of manufacturing a multi-layered helmet are provided. These methods may include molding a standard-shaped flexible inner layer to conform to the inner surfaces of a plurality of collapsible members and of a rigid outer shell. The methods may allow a user to quickly develop a custom-fitting helmet using the head of the wearer and an inner surface of nearly any configuration of outer shell and collapsible members. In some embodiments, the layers of the helmet may be removably attached to each other using pin inserts. The pin inserts may comprise shear breakage sections configured to break upon application of a significant shear stress caused by relative translational or rotational movement between the layers they are holding together. This breakage may further absorb energy of an impact and help protect the wearer in dangerous conditions.

The present description provides examples, and is not limiting of the scope, applicability, or configuration set forth in the claims. Thus, it will be understood that changes may be made in the function and arrangement of elements discussed without departing from the spirit and scope of the disclosure, and various embodiments may omit, substitute, or add other procedures or components as appropriate. For instance, the methods described may be performed in an order different from that described, and various steps may be added, omitted, or combined. Also, features described with respect to certain embodiments may be combined in other embodiments.

Referring now to the figures in detail, FIGS. 1 and 2 illustrate a bicycle helmet 100 according to an exemplary embodiment of the present disclosure. Other types of helmets (e.g., ski helmets and motorcycle helmets) may be implemented using the features of helmet 100, as will be appreciated by those having skill in the art. FIG. 1 is a perspective view of the helmet 100, and FIG. 2 is a bottom view. The helmet 100 includes an outer shell 102 and a collapsible layer 104 comprised of multiple collapsible pad members 106, 108, 110, 112, 114. In some embodiments, the helmet 100 may also have a chin strap 116 and neck guard 118. These elements are not shown in FIG. 2. The helmet 100 is shown in FIGS. 1 and 2 without a flexible inner liner interior to the collapsible pad members 106, 108, 110, 112, 114.

The outer shell 102 may comprise a rigid, durable material. For example, the outer shell 102 may comprise a metal such as aluminum, a rigid plastic such as polycarbonate, or a rigid composite such as a carbon fiber or fiberglass composite. Composite materials may beneficially retain their shape after initial impact due to their bonded strands maintaining a barrier to stop abrasion and penetration after the initial impact.

The outer surface of the outer shell 102 may be configured with graphic designs, similar to a team helmet. The outer shell 102 may take a shape generally conforming to the shape of a human head while resisting bending and other inward deflection. In some embodiments, the outer shell 102 may keep its shape integrity under impacts of about 490 Newtons (50-g) to about 4093 Newtons (500-g), and more particularly about 2942 Newtons (300-g) to about 3923 Newtons (400-g) or more. Beyond this range, the outer shell 102 may be configured to crush on impact but maintain a consistent and connected form (i.e., it will resist cracking and shattering) as a protection against penetration and abrasion of the portions of the helmet 100 beneath the surface. This consistent and connected form may be compared to chainmail armor in that it continues to be a consistent barrier against or stopping penetration even after it deforms to a different shape in response to an impact. An outer shell may need to be replaced after sustaining an impact, but at that point it will have provided protection to the wearer by crushing and absorbing energy that otherwise could have caused serious (or more serious) injury to the wearer.

Because the collapsible pad members 106, 108, 110, 112, 114 may comprise a brittle material, the outer shell 102 may be positioned exterior to the pad members to protect them from incidental damage (e.g., scratches or small bumps). In some embodiments, the outer shell 102 may comprise holes or other openings for stress relief or to allow ventilation through the shell surface. The outer shell 102 may also have protrusions and depressions to increase stiffness, improve aerodynamics, and/or to allow the pad members 106, 108, 110, 112, 114 to be more easily attachable to its inner surface. For example, the shape of the outer shell 102 may comprise slots in which specific pad members 106, 108, 110, 112, 114 are individually attachable based on their shape. Thus, the assembly of the helmet may be simplified. In cases where the outer shell 102 has been significantly damaged or disfigured, the modular inner components of the helmet 100 may be removed and reattached to another outer shell 102.

In the embodiment shown, the collapsible pad members 106, 108, 110, 112, 114 are arranged to generally cover the inner surfaces of the outer shell 102. Broken lines are used to indicate the presence of a pad member beneath the outer surface of the helmet 100 in FIG. 1. The shape and size of the pad members is provided here for illustration purposes. Typically, about four to about twelve pad members is sufficient. In other embodiments, the pad members may be thicker, have different boundaries, be present in a different number or position, and so on. For example, in some embodiments, there may be no crown member 114 to allow for additional ventilation in the helmet 100. However, in this exemplary embodiment, the pad members are configured to be replaceable in the helmet 100 in positions likely to sustain an impact. For example, the rear pad member 112 may be shaped to be the only pad member deformed in an impact to the rear portion of the helmet 100, so that in such an impact, the rear pad member 112 is the only pad member that requires replacement. Similarly, the other pad members 106, 108, 110 may be shaped and positioned in the helmet 100 in a manner that minimizes waste when the helmet 100 is subjected to common impacts.

In some embodiments, the collapsible pad members 106, 108, 110, 112, 114 may comprise a rigid foam, such as, for example, Styrofoam, a cellular material, expanded polystyrene (EPS) or expanded polypropylene (EPP). The collapsible pad members 106, 108, 110, 112, 114 may alternatively or additionally comprise other materials, such as other plastics, foams, wood composite, other composites, or another like material. The materials used may beneficially be light and rigid, yet crushable, foldable, collapsible, snappable, or able to accordion under high stresses. The pad members 106, 108, 110, 112, 114 may be beneficially comprised of a material designed to deform at forces in a range of about 490 Newtons (50-g) to about 1961 Newtons (200-g). Thus, upon crushing of the outer shell 102, the pad members 106, 108, 110, 112, 114 may collapse to further absorb energy from the deflecting outer shell 102 and prevent the wearer's head from sustaining the full strength of the blow. Alternatively, in lower impacts that do not deform the outer shell 102, the pad members 106, 108, 110, 112, 114 may deform before the outer shell 102 deforms to prevent low-impact or whiplash-type injuries (such as concussions) that tend to be more common and unreported than high-speed or high-impact events. The collapsible pad members 106, 108, 110, 112, 114 may be formed solid or may comprise voids or varying thickness profiles. Thus, in some embodiments they may collapse into voids within their general shape, break down, fold, snap, accordion, or make other similar deformation. Some of these section types are disclosed in connection with FIGS. 10A-10K and 11, infra. The deformation of the pad members 106, 108, 110, 112, 114 may permit rotational or translational movement of the outer shell relative to the flexible inner liner, or may permit rotational or translational movement of the flexible inner liner relative to the rigid outer shell. In at least some embodiments, the pad members may be connected to outer shell and/or flexible inner liner in a way that permits relative rotational and/or translational movement before deformation of the pad members.

The crushing and movement of the outer shell and collapsible pad members may absorb or redirect much of the initial rotational forces in an impact because the crushing of the shell and pad members may absorb these rotational forces. Thus, much of the rotational movement of the head that is delivered to the brain may be reduced, and the head and brain may rotate less and more slowly in an impact.

FIG. 3 is a cross section of a helmet 300 according to another embodiment of the present disclosure. This embodiment illustrates that the helmet 300 may have a different design from helmet 100, since helmet 300 is similar to a motorcycling helmet with additional protection extending down the lateral sides of the helmet, as indicated by the dashed line. The helmet 300 may comprise a rigid outer layer 302, collapsible pad members 306, 312, 314, and a flexible inner layer 320. In this embodiment, the rigid outer layer 302 may have similar characteristics to the outer shell 102 of FIG. 1. Likewise, the pad members 306, 312, 314 may have the characteristics described in connection with the collapsible pad members of FIG. 1.

The flexible inner layer 320 may comprise a moldable foam layer that has been shaped to have an inner surface 322 with a specified molded profile. For example, the inner surface 322 may be molded to the shape of the surfaces of a particular wearer's head, as further described in connection with FIG. 5. The flexible inner layer 320 may act as a cushion for the comfort of the wearer. Therefore, the flexible inner layer 320 may be more flexible than the pad members 306, 312, 314. The inner layer's flexibility may allow the wearer to more easily don and doff the helmet even though the inner surface 322 closely follows the surface of the wearer's head. The flexible inner layer 320 may comprise holes or voids in its surfaces to increase ventilation through its surfaces or to wick moisture from the wearer's head.

The flexible inner layer 320 may extend into voids 330, 332 between the collapsible pad members 306, 312, 314 using fill members 334, 336. The fill members 334, 336 may be formed as peaks or ridges in the outer surface 324 (see also FIG. 4) of the flexible inner layer 320. In some embodiments, the fill members 334, 336 may completely fill the voids 330, 332, but the fill members 334, 336 may alternatively only partially fill them (as shown). Filling the voids 330, 332 may improve the feel of the helmet 300 and provide additional shock absorption in the areas between the collapsible pad members 306, 312, 314 in the event of an impact. It may also help stabilize the collapsible pad members 306, 312, 314 in the case of an impact by keeping them securely positioned relative to the head and the outer layer 302. The fill members 334, 336 may also assist a user in locating the position on the helmet at which the collapsible pad members 306, 312, 314 should be attached upon initial assembly or replacement after deformation. See also FIG. 4, showing that the flexible inner layer 320 has pad-member-shaped recesses in its outer surface 406. In various embodiments the fill members 334, 336 may extend partially towards or completely into contact with the inner surface of the outer layer 302. In other embodiments, flexible inner layer 320 is void of fill members 334, 336 and has a generally smooth, uninterrupted outer surface 406.

The flexible inner layer 320 may comprise a flexible shock-absorbent material, such as a high-density foam rubber or expanded polymer. In some embodiments, the flexible inner layer 320 may comprise moldable foams, plastics and ceramics. These foams are preferably moldable, depending on their properties, by heating them up (inducing flexibility), and forming them to a specific shape. The material may then maintains its soft form once it cools. The material may also be formed using a vacuum technique that can set and maintain a soft and flexible shape. In another example, a chemically activated foam material may be used that heats up when two basic components mix and then are formed into a custom and flexible shape that is maintained once it cools or sets.

FIG. 4 is an exploded section view of helmet 300. The rigid outer layer 302, collapsible pad members 306, 312, 314, and flexible inner layer 320 are separated from each other to illustrate their individual shape characteristics. The outer layer 302 has an inner surface 400 on which the collapsible pad members 306, 312, 314 may be attached. In some embodiments, the inner surface 400 may be textured (e.g., scored or ridged) to improve adhesion between the pad members or other connection means (e.g., one side of a hook and loop fastener pad) and the inner surface 400. The inner surface 400 may also comprise openings to receive snap-fit pins or may comprise the snap-fit pins themselves, as shown in greater detail in connection with FIGS. 7-8. These openings may be reinforced with pliable washer-type material or eyelet pieces that provide reinforcement that supports and accepts the connection of the various different helmet components. These eyelets, rivets, and other pieces may have a plastic or rubber liner structure and coating to give added strength and/or reinforcement for easier and better connectivity. The outer layer 302 is not intended to be shown to scale and may be thicker than shown, such as for purposes of accommodating the needs of various fastening and connection devices shown herein (see, e.g., outer shell 802 of FIG. 8).

The collapsible pad members 306, 312, 314 may each comprise an outer surface 402 and an inner surface 404. The outer surfaces 402 may be shaped to conform to the inner surface 400 of the outer layer 302 or to attachment surfaces (e.g., holes/grooves, or pegs/ridges) on the inner surface 400. The inner surfaces 404 may be shaped to provide sufficient thickness to each collapsible pad member 306, 312, 314 to provide necessary energy absorption characteristics for the portion(s) of the wearer's head that are positioned adjacent thereto when the helmet 300 is being worn. For example, the front pad member 306 may be thicker than the crown pad member 314 when it is anticipated that higher impact energy will be experienced by the front of the helmet 300 in a serious collision than the crown pad member 314. Other characteristics of the pad members 306, 312, 314 may vary from pad member to pad member as well, such as density, crush propensity, interior void profile, and the means by which they are individually attached to other portions of the helmet 300. Profile shapes of the pad members 306, 312, 314 are discussed in further detail in connection with FIGS. 10A-10K and 11, infra.

The outer and inner surfaces 402, 404 may also be configured to accommodate attachment between the outer layer 302 and the collapsible pad members 306, 312, 314 and/or the inner layer 320 and the collapsible pad members 306, 312, 314. Various embodiments of attachment structures are discussed in connection with FIGS. 5-7, infra. Alternatively, the outer and inner surfaces 402, 404 may be attached to the inner surface 400 or outer surface 406 using an adhesive, magnets, or another semi-permanent attachment means. For example, a bonding agent (e.g., adhesive) may be used that provides enough of a connection to keep the surfaces connected during regular use, but can release when a threshold force is applied to pull the bonded elements apart. In some embodiments, the collapsible pad members 306, 312, 314 may be attachable to the outer layer 302 and/or flexible inner layer 320 using bolts, screws, clips, brackets, wrapped or tied wire or filament, cables, straps, suction cups, buttons, zip ties, clamps, clasps, retaining rings, staples, snaps, twist ties, and similar connectors. Some arrangements may use a pocket and tab configuration wherein tabs extending from the collapsible pad members 306, 312, 314 may be inserted into (or rotated into) pockets in the outer shell 302. See FIGS. 9A-9B and their related descriptions infra.

In some embodiments, the outer surfaces 402 may use a different means or method of attachment than the inner surfaces 404. For example, the outer surfaces 402 may use snap-fit pins to connect with the outer layer 302 and the inner surfaces 404 may use hook and loop fasteners to connect with the flexible inner layer 320. Similarly, even if both surfaces 402, 404 use the same attachment means, one surface may be more securely or strongly attached than the other. For instance, the outer surface 402 may comprise more snap-fit connectors than the inner surface 404, or the outer surface 402 may comprise more hook and loop fastener material (or hook and loop fastener material having stronger grip) than the inner surface 404. The grip of a hook and loop fastener material may be based on the length of loops or hooks in the material. The length of the hook and loop fibers may also allow for different degrees of movement between the layers. This may provide added relief form rotational impacts. These embodiments may beneficially facilitate removal of the flexible inner layer 320 without simultaneously removing the collapsible pad members 306, 312, 314, such as when the flexible inner layer 320 is removed for cleaning or due to needing replacement. In one embodiment, the flexible inner layer 320 may be exchanged based on the user, so that two users may quickly exchange between flexible inner layers that conform to their individual heads.

Alternatively, the attachment of the collapsible pad members 306, 312, 314 may be more secure to the flexible inner layer 320 than to the outer layer 302. This may potentially allow the user to more easily identify collapsible pad members needing replacement (such as when they crush first at their outer surfaces 402) since the pad members 306, 312, 314 would tend to detach from the inner surface 400 of the rigid outer layer 302 before detaching from the flexible inner layer 320. This configuration may also be beneficial in embodiments where users desire to exchange or customize the outer shell, such as when a thicker or thinner design is used for certain activities, for different connection means, or for cosmetic reasons.

In embodiments where the connection between the outer layer 302, pad member layer (comprising the pad members, e.g., 306, 312, 314), and flexible inner layer 320 may vary in strength or connection type from layer to layer or between specific pad members and the outer and inner layers 302, 320, the differences in connections may provide convenience to the user. For example, the connection between layers may be designed to absorb different amounts of energy, such that one layer or portion of the helmet 300 may detach the layers more easily in response to a certain force (e.g., a rotational force or low-level impact) than to another force (e.g., a direct/axial force or higher-strength impact). Thus, the differing connections between layers may be a safety feature or may make the helmet more comfortable and shock absorbent when the helmet 300 is impacted by a lower impulse than is theoretically sustainable by the helmet 300.

FIG. 5 illustrates an embodiment of a helmet 500 prior to final formation of a flexible inner layer. A rigid outer layer 302 is provided attached to a plurality of collapsible pad members 306, 312, 314. An unmolded blank of a flexible inner layer 520 may comprise a moldable foam configurable to conform to the inner surfaces of the collapsible pad members 306, 312, 314 and the surface of a wearer's head 550. For example, the moldable foam may be configured to become pliable in response to heat, and the helmet 500 may be pressed upon the flexible inner layer 520 and upon wearer's head 550 to allow the inner layer 520 to plastically deform on contact. In one embodiment, the flexible inner layer 520 may be molded as shown in FIGS. 3-4, having fill members 334, 336. Thus, the thickness of the flexible inner liner may vary when measured relative to the inner surface of the rigid outer shell, where portions such as the fill members 334, 336 are thicker than other portions of the liner. Methods of manufacturing these helmets are also described in more detail infra.

In another embodiment, the flexible inner layer may be formed by a molding process where the outer layer 302 and collapsible pad members 306, 312, 314 are positioned around the head 550 without a flexible inner layer 520 interposed between. The head 550 may be covered by a thin protective liner. Foam or a gel-like substance may then be injected between the collapsible pad members 306, 312, 314 and the wearer's head 550 which sets in place between the pad members 306, 312, 314 and the outer layer 302 and forms a flexible inner layer formed to the surfaces it contacts. Using this process, the flexible inner layer may be easily formed around connection pins extending from the collapsible pad members 306, 312, 314 (see FIGS. 7-8), and the flexible inner layer may more readily fill spaces between the pad members 306, 312, 314.

FIGS. 6-8 are partial cross-sectional illustrations of various ways in which multiple layers of a helmet may be attached to each other. In FIG. 6, the rigid outer layer 602, collapsible pad member 606, and flexible inner layer 620 are attached to each other using hook and loop fastener material 610, 612. The hook and loop fastener material 610 between the outer layer 602 and the collapsible pad member 606 may have different surface coverage, gripping strength, and positioning than the hook and loop fastener material 612 between the collapsible pad member 606 and the flexible inner layer 620. In some embodiments, the hook and loop fastener material 610, 612 may entirely cover the surfaces of the layers 602, 606, 620 that come into contact with each other, and, as discussed above, the hook and loop fastener material 610, 612 may have different grip strengths for different portions of the helmet or for individual collapsible pad members. The hook and loop fastener material 610, 612 is typically attached to portions of the helmet by an adhesive or by sewing.

Some layers may comprise ridge and groove fasteners in addition to, or in place of, hook and loop fasteners. For example, the flexible inner layer 620 and collapsible pad member 606 may comprise one or more interlocking ridge 650 and groove 652. The ridge and groove fasteners may comprise materials that differ from the remainder of the layers (e.g., the flexible inner layer 620 and collapsible pad member 606), such as comprising a flexible plastic that can securely yet removably interlocking ridges 650 and grooves 652 when they are pressed together. The ridges and grooves may be releasably attachable to each other to facilitate disassembly and replacement of collapsible pad members or other modular components of the helmet. Including ridge and groove fasteners may increase the strength of the connection between two layers and absorb impact energy if they disconnect in response to an applied force. In some embodiments, the ridge and groove fasteners may connect a collapsible pad member to the outer shell, and in some cases the ridge and groove fasteners may be the only attachment means connecting the layers.

FIG. 7 illustrates an embodiment where the rigid outer layer 602, collapsible pad member 606, and flexible inner layer 620 are connectable to each other using snap-fit connectors 700. The snap-fit connectors 700 extend from surfaces of the flexible inner layer 620 and the outer layer 602 toward the collapsible pad member 606 at positions corresponding with openings 702 in the collapsible pad member 606. The openings 702 may correspond to positions on the collapsible pad member 606 that securely attach the collapsible pad member 606 to the outer layer 602 and the flexible inner layer 620. The openings 702 and corresponding snap-fit connectors 700 may be flexible enough to resiliently receive (i.e., snap into) each other, but then cause an interference fit that keeps the layers linked to each other unless a sufficient axial force is applied to a connector 700 to remove it from its opening 702. The snap-fit connection between the connectors 700 and the openings 702 may differ in each collapsible pad member 606 of the helmet, and may be stronger between different layers as well. For example, the snap-fit connection between the outer layer 602 and the pad member 606 may require more force to disconnect than the snap-fit connection between the flexible inner layer 620 and the pad member 606.

FIG. 8 illustrates another embodiment of a snap-fit between layers of a helmet of the present disclosure. A rigid outer shell 802 is external to a collapsible pad member 806 which is in turn external to a flexible inner layer 820. Snap-fit pin inserts 800 are disposed between the layers and are insertable into cavities 822 in each layer. The snap-fit pin inserts 800 and cavities 822 may be similarly received by each other as the snap-fit connectors 700 and openings 702 of FIG. 7. The pin inserts 800 may also comprise a shear breakage section 805 configured to break in response to an applied shear force. For example, the pin inserts 800 may be configured to break in response to sufficient relative rotational movement of the outer shell 802 and the collapsible pad member 806 to apply the shear force to the shear breakage sections 805 of the pin inserts 800. These sections 805 may provide additional resistance to relative rotational movement of the layers without completely restricting the relative rotational movement upon reaching a sufficient threshold shear stress. These sections 805 may absorb energy in the helmet upon breakage and help to lessen the forces experienced by the wearer's head. The pin inserts 800 may be removable or exchangeable in the cavities 822, so some portions of the helmet may be configured to have greater resistance to breakage than other potions, the pin inserts 800 may be replaceable upon breakage, and different pin inserts 800 may be used between each layer to give the helmet different attachment and breakage properties in inner areas of the helmet than in areas further outward.

FIGS. 9A and 9B show an exemplary collapsible pad member 900 using tab and pocket connectors. The collapsible pad member 900 may be one of pad members 106, 108, 110, 112, 114, 306, 312, 314, 606, 806 shown elsewhere herein. Connector tabs 902 extend from the periphery of the pad member 900 in positions configured to rotate into pockets 904 in the inner surface of a rigid outer shell 906. The tabs 902 and pockets 904 may be configured to slide or snap into position upon rotation of the collapsible pad member 900 with the tabs 902 adjacent to the pockets 904. While three tabs 902 are shown in these figures, other pad members or other embodiments of the pad member 900 shown may comprise more or fewer tabs 902 with a corresponding number of pockets 904. Use of tab and pocket connectors may allow users to quickly and easily insert and remove collapsible pad members 900. The tabs 902 may also be configured to break upon a sufficient impact, thereby absorbing some of the energy of the impact in addition to other energy absorption elements of the helmet.

FIGS. 10A-10K show exemplary cross-sectional profiles of collapsible pad members (e.g., pad members 106, 108, 110, 112, 114, 306, 312, 314, 606, 806). The profiles illustrate how various embodiments may include shape profiles in addition to other features (e.g., density, thickness, and position) in order to affect the crush and deformation characteristics of the pad members. The profiles may each comprise a lower surface 1000 and an upper surface 1002. Generally, the lower surface 1000 is relatively smooth and configured to conform to the inner surface of a rigid outer layer. For example, the lower surface 1000 may be partially spherical or ellipsoidal to follow the inner surface of a partially spherical or ellipsoidal rigid outer layer. The upper surface 1002 is relatively textured and may comprise peaks, ridges, cones, valleys, and other shapes similar to those pictured in these figures. The upper surface 1002 is typically oriented to face inward in a helmet. In some embodiments, the lower surface 1000 may also be textured, as illustrated in FIG. 10D. Generally, increasing the thickness of the ridges or peaks increases the rigidity of the collapsible pad members and therefore makes them more resistant to deformation. Layers of pad members may be linked or stacked to form a single structure, such as the structure shown in FIG. 11. Tests by the inventors indicate that preferable profile embodiments include the embodiments of FIGS. 10D, 10G and 11 which are measurably more shock absorbent under multiple tests than other examples shown.

A profile of FIG. 10A may be referred to as having a semicircular pattern. Other patterns may include rounded sawtooth (FIG. 10B), spaced sawtooth (FIG. 10C), double spaced sawtooth (FIG. 10D), elbow (FIG. 10E), narrow rectangular (FIG. 10F), broad rectangular (FIG. 10G), jagged triangular (FIG. 10H), angled triangular (FIG. 10I), truncated pyramidal (FIG. 10J), pyramidal (FIG. 10K), and zigzag (FIG. 11). In one embodiment, a “bird nest” design may be used that features overlapping and intertwining segments. While the characteristics of collapsible members having these profiles may vary based on their rigidity, materials of construction, thickness, and other features, for the sake of example in this disclosure, the embodiments of FIGS. 10A-10D, 10E-10G, and 10H-10K may be characterized as forming collapsible members that permanently deform by crushing, and the embodiments of FIGS. 10D-10E and 11 may be said to be collapsible members that deform by folding, breaking, or snapping. Assuming that each profile is constructed of the same material, these are likely outcomes of how each of the profiles will react to a powerful impulse. A breakage or snapping connotes that the profile dissipates energy on impact by fracturing or breaking, and a crushing or folding describes dissipation of energy on impact by changing shape, absorbing an impact, crushing voids or flexible material spaced within the profile, or the like. The embodiments of FIGS. 10D-10E and 11 may beneficially provide lateral dispersion of energy in reaction to a vertical applied force and may therefore be more energy absorbent than other profiles. Additionally, while FIG. 11 is the only example shown having multiple tiers or staggered levels, any of the embodiments of FIGS. 10A-10K may be modified to support multiple crush layers within a single collapsible member.

According to some embodiments, a method of manufacturing a multi-layered helmet for deformably absorbing an impact to a head of a wearer may be performed by providing a rigid outer shell, a plurality of collapsible members, and a flexible inner liner. The rigid outer shell may have an inner surface to which the plurality of collapsible members may be attached. The collapsible members may be permanently deformable to absorb impact energy in response to a force applied to the rigid outer shell. The flexible inner liner may be attached to the inner surfaces of the plurality of collapsible members.

In some cases, the attachment between the collapsible members and the outer shell and/or flexible inner liner may be removable attachment, such as by hook and loop fasteners, pin inserts, snap-fit connectors, interlocking ridges and grooves, or other removable attachment means. For example, the method may include providing a plurality of pin inserts, forming a plurality of cavities or openings in the plurality of collapsible members that are shaped to receive the pin inserts, and inserting the pin inserts into the plurality of cavities and into the rigid outer shell and flexible inner liner. The pin inserts then removably secure the collapsible members to the rigid outer shell and flexible inner liner. In some embodiments the removable attachment between the collapsible members and the rigid outer shell is more secure or more difficult to detach than the removable attachment between the collapsible members and the flexible inner liner.

The method may also include shaping the flexible inner liner to conform to the inner surfaces of the plurality of collapsible members and to a surface of the head of the wearer. Thus, the flexible inner liner may comprise expansion portions that expand into (or are molded into) voids between the plurality of collapsible members and the head of the wearer. An unfinished flexible inner liner may for example be heated to a temperature allowing at least temporary plastic deformation, then pressed into contact with the inner surfaces of the collapsible members and/or the rigid outer shell. The unfinished flexible inner liner may then deform upon contact, filling grooves and apertures on the surface (or receiving protrusions thereon) of the collapsible members and at least partially retain the molded shape after cooling or curing (i.e., stiffening). The material used in the flexible inner liner may be a lightweight foam or gel material that will maintain its form and shape, but also have elastic flexibility and stretch to provide comfort. The wearer's head may be simultaneously pressed against the inner surface of the unfinished flexible inner liner to mold the liner into conformity with the head surfaces, though in some embodiments, the head contacting surfaces of the flexible inner liner may be separately formed or molded at a different time.

In another embodiment, the flexible inner liner may be formed by covering or filling the voids and surfaces around the collapsible members with shape-filling material, such as a fluid, foam, paste, gel, clay-like material, or other material that can take the shape of the interior of the helmet. The shape-filling material may be injected or pushed between the collapsible members, between the head of the wearer and the collapsible members, or by another method known in the art. In some arrangements, a foam material is used that may be in a flowable form stored under pressure in a canister. The flowable material can be extruded from the canister and placed in a soft foam liner. The material may then set or cure to have the desired characteristics. Curing or setting of the material may be through a chemical reaction, light activation, or air activation, depending on the particular formation of the foam material. The shape-filling material may be part of the finished flexible inner liner by forming the shape of the outer surface of the inner liner that faces the collapsible members, and also potentially forming the shape of the inner surface that faces the wearer. By using a shape-filling material, the helmet may be made more solid and have a more precise fit to the wearer and to the inner surfaces of the collapsible members and outer shell.

In one embodiment, the liner material may be a lightweight synthetic elastic material that can be designed in pocket form. The pocket form may be able to have expandable foam injected into the picket such that the soft foam liner can take the size and shape of an individual's head. For example, the liner may be fitted and filled with foam in a stationary hard mold simulating a rigid outer shell to facilitate proper fit and fill to the size and shape of the individual wearer's head. The flexible inner liner may also comprise a material at its surface that is soft, breathes, and wicks away moisture. The shape of the liner may include vents for air circulation.

The helmet may be manufactured with different types of collapsible members being attached at different positions in the helmet. For example, one portion of the collapsible members having a greater rigidity than another portion may be attached to inner surfaces of the outer shell that require additional rigidity in their energy absorption characteristics. In some examples, the collapsible members themselves may have custom fit features formed therein as opposed to having the custom fit features formed solely in the flexible liner as discussed above.

When one of the collapsible members is deformed or damaged, such as after an impact, the method of replacing the collapsible member may include a step of detaching the flexible inner liner from the inner surfaces of the plurality of collapsible members, then detaching a first consumed first collapsible member from the inner surface of the rigid outer shell or the outer surfaces of the flexible inner liner. The consumed collapsible member may be individually detachable from the rest of the collapsible members. Next, the consumed first collapsible member may be replaced by a second collapsible member that has an equivalent shape to the first collapsible member. The second collapsible member may thus be a replacement part for the helmet that matches or closely imitates the shape and other characteristics of the first collapsible member. Finally, the flexible inner liner may be reattached to the inner surfaces of the plurality of collapsible members.

In another embodiment, the flexible inner liner may be removed from the helmet simultaneously with the collapsible members, which are attached to the outer surface of the flexible inner liner. Thus, the flexible inner liner and the collapsible members may be removed together from the outer shell. This may be beneficial when the collapsible members are likely to become detached from the outer shell upon their deformation and yet are likely to remain attached to the flexible inner liner at the same time. This embodiment may also facilitate replacement of the consumed collapsible member since the flexible inner liner may have extension portions that extend around the area of the flexible inner liner that is supposed to receive the replacement collapsible member. Therefore, these extension portions may act as a guide for the positioning of the new collapsible member prior to reinsertion of the flexible inner liner into the helmet.

FIGS. 12A-12M show photographs of exemplary test members for the profile shapes of FIGS. 10A-10K and 11. FIG. 12A is a control member of a solid block of foam, and 12B-12M are members that correspond with the profile shapes of FIGS. 10A-10K and 11, respectively. In FIGS. 12A-12M, the foam members were tested by dropping a ball from a height of 0.5 meters and 1.0 meters onto foam members having the profiles shown comprised of 2-pound or 3-pound density styrofoam. The figures show the permanent deformation and crush of each type of profile after testing was completed. Thus, each figure shows the effects of an equivalent impact on each profile shape. The embodiment of FIG. 12M was particularly crushed and broke or folded in response to the impact of the test ball. The following table displays test results obtained when testing the foam members of FIGS. 12A-12M.

2-lb. 2-lb. 3-lb. 3-lb. Member - Member - Member - Member - Module Label 0.5 m Drop 1.0 m drop 0.5 m drop 1.0 m drop Control 55.0 88.2 77.1 113.0 Module 1A 58.5 334.0 67.5 132.0 2A 59.5 308.0 61.5 114.5 3A 212.5 553.0 94.0 406.5 4A 46.0 306.0 52.5 107.0 5A 122.0 479.0 89.0 327.5 6A 56.0 162.5 54.5 225.5 7A 54.0 99.5 57.0 120.5 8A 227.0 484.0 89.0 377.5 8B 64.0 395.5 67.5 163.0 10A  50.0 312.0 45.0 99.0 11A  153.0 402.0 69.0 441.0 12A  235.5 549.5 220.0 592.0

The module labels are shown in FIGS. 12A-12M. The tabulated data is the maximum g-forces (measured in g-scale) transferred from the dropped ball through the module to an accelerometer. Thus, the foam members tested that improved protection over the block-shaped control module have lower g-forces registered than the control module. This means that module 10A (corresponding with FIG. 12M) had the best performance, followed by modules 4A and 6A (corresponding with FIGS. 12E and 12G, respectively).

FIGS. 13A-13B show another embodiment of a collapsible member 1300 configured to be attachable to an outer shell of a helmet of another embodiment of the present disclosure. The member 1300 comprises a first impact layer 1302 and a second impact layer 1304. The second impact layer 1304 may be designed to crush or otherwise permanently deform when a force that could cause a head injury is applied. For example, as illustrated in FIG. 13B, when an impact that is sufficient to cause head injury is applied to the second impact layer 1304, the material may collapse and crush, and in the process may absorb the energy from the impact and protect the wearer's head. Should the wearer experience a higher force impact, the second impact layer 1304 may collapse and allows the wearer's head to engage the first impact layer 1302 to further protect the wearer's head and absorb additional energy.

As illustrated in FIGS. 13A and 13B, the second impact layer 1304 may have a “bird nest”-like design that features overlapping and intertwining collapsible segments. The bird nest configuration may allow the second impact layer 1304 to absorb impact by crushing onto itself. The second impact layer 1304 may also comprise segments configured to collapse, crush, or have stress points designed to break in a sufficient impact. The impact layers may be molded and made from the same material in one piece or may be attached to each other.

FIG. 14 illustrates another embodiment of a second impact layer 1304 of FIG. 13. The second impact layer 1304 may comprise rods, pistons, and/or core/tubular structures 1400. These structures 1400 may be woven together in the bird nest configuration or may be freestanding. The structure and shape of the structures 1400 may allow material to collapse, crush, accordion, and break apart to absorb energy from an impact. The tiered pillar design may allow variable resistance to crushing and other deformation or breaking, so that the structures 1400 may break or crush more gradually and absorb the energy of both lesser and greater impacts.

FIG. 15 illustrates another embodiment of a second impact layer 1304 of FIG. 13. In this case, the second impact layer 1504 comprises a plurality of interlinked cellular structures. The structures may have a honeycomb design having an irregular surface shaped to conform to the outer surface of a flexible inner liner, as shown generally by the dashed line. The thickness of the cellular structures may also vary based on the area of the helmet in which the pad member having the second impact layer 1504 may be attached. For example, a thicker layer of cellular structures may be positioned where the wearer's head is most likely to sustain a low-force impact. The cellular structures may be configured to collapse and crush into contact with each other and the first impact layer 1502.

FIGS. 13A-13B, 14, and 15 illustrate how collapsible pad members (e.g., pad members 106, 108, 110, 112, 114, etc.) may be configured for withstanding a single impact and then would be need to replaced. These pad members may be easily and inexpensively produced so that the helmet may be used in many impacts at full capacity and without frustrating the user who needs a replacement pad member.

The previous description of the disclosure is provided to enable a person skilled in the art to make or use the disclosure. Various modifications to the disclosure will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other variations without departing from the spirit or scope of the disclosure. Throughout this disclosure the term “example” or “exemplary” indicates an example or instance and does not imply or require any preference for the noted example. Thus, the disclosure is not to be limited to the examples and designs described herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein. 

What is claimed is:
 1. A multi-layered helmet for deformably absorbing an impact to a wearer, the multi-layered helmet comprising: a rigid outer shell having an inner surface; a plurality of collapsible members, the collapsible members permanently deformable in response to an applied force, the deformation absorbing impact energy from the applied force, the plurality of collapsible members being individually attachable to and removable from the inner surface of the rigid outer shell, wherein the plurality of collapsible members are individually replaceable upon being permanently deformed; a flexible inner liner having an outer surface and an inner surface, the plurality of collapsible members being individually attachable to and removable from the outer surface of the flexible inner liner, the inner surface of the flexible inner liner being configured to rest against the heard of a wearer.
 2. The multi-layered helmet of claim 1, further comprising: a plurality of voids formed at least in part by spaces between the plurality of collapsible members; wherein the flexible inner liner comprises extension portions extending toward the rigid outer shell and fitting within the plurality of voids.
 3. The multi-layered helmet of claim 1, wherein the permanent deformation of at least one of the plurality of collapsible members is a breakage or a snapping of the least one of the plurality of collapsible members.
 4. The multi-layered helmet of claim 1, wherein at least one of the plurality of collapsible members is permanently deformed by a crushing or a folding of the at least one of the plurality of collapsible members.
 5. The multi-layered helmet of claim 1, wherein the plurality of collapsible members are removably attachable to the rigid outer shell and the flexible inner liner by hook and loop fasteners covering at least a portion of the inner surface of the rigid outer shell, the plurality of collapsible members, and the outer surface of the flexible inner liner.
 6. The multi-layered helmet of claim 5, wherein a first portion of the hook and loop fasteners removably attaches at least one of the plurality of collapsible members to the rigid outer shell and a second portion of the hook and loop fasteners removably attaches the at least one of the plurality of collapsible members to the flexible inner liner, the first and second portions having different attachment strengths.
 7. The multi-layered helmet of claim 1, wherein the plurality of collapsible members are removably attachable to the rigid outer shell and the flexible inner liner by a plurality of snap-fit connectors extending between the rigid outer shell, the plurality of collapsible members, and/or the flexible inner liner.
 8. The multi-layered helmet of claim 7, wherein the plurality of snap-fit connectors are pins having a shear breakage section configured to break in response to an applied shear force, the shear breakage section being positioned to be subjected to an applied shear force when the plurality of collapsible members translate relative to the rigid outer shell or the flexible inner liner.
 9. The multi-layered helmet of claim 8, wherein the plurality of snap-fit connectors are removably insertable into openings in the plurality of collapsible members.
 10. The multi-layered helmet of claim 1, wherein the plurality of collapsible members are removably attachable to the rigid outer shell and the flexible inner liner by a releasable ridge-and-groove connector.
 11. The multi-layered helmet of claim 1, wherein the flexible inner liner has varying thickness when measured relative to the inner surface of the rigid outer shell.
 12. The multi-layered helmet of claim 1, wherein a first portion of the plurality of collapsible members has a different rigidity than a second portion of the plurality of collapsible members.
 13. The multi-layered helmet of claim 1, wherein the plurality of collapsible members collapse to permit rotational or translational movement of the flexible inner liner relative to the rigid outer shell.
 14. The multi-layered helmet of claim 1, wherein the plurality of collapsible members collapse to permit rotational or translational movement of the outer shell relative to the flexible inner liner.
 15. The multi-layered helmet of claim 1, further comprising a chin strap configured to secure the helmet to a head of the wearer.
 16. A method of manufacturing a multi-layered helmet for deformably absorbing an impact to a head of a wearer, the method comprising: providing a rigid outer shell having an inner surface; attaching a plurality of collapsible members to the inner surface of the rigid outer shell, the plurality of collapsible members being permanently deformable to absorb impact energy in response to a force applied to the rigid outer shell, the plurality of collapsible members having inner surfaces; attaching a flexible inner liner to the inner surfaces of the plurality of collapsible members.
 17. The method of claim 16, wherein attaching the plurality of collapsible members and attaching the flexible inner liner comprises removably attaching the plurality of collapsible members and removably attaching the flexible inner liner, respectively.
 18. The method of claim 16, wherein removably attaching the plurality of collapsible members further comprises: providing a plurality of pin inserts; forming a plurality of cavities in the plurality of collapsible members, the plurality of cavities being shaped to receive the pin inserts; inserting the plurality of pin inserts into the plurality of cavities and into the rigid outer shell and flexible inner liner, the pin inserts removably attaching the plurality of collapsible members to the rigid outer shell and to the flexible inner liner.
 19. The method of claim 16, wherein the plurality of collapsible members are more securely removably attached to the rigid outer shell than to the flexible inner liner.
 20. The method of claim 16, further comprising: shaping the flexible inner liner to conform to the inner surfaces of the plurality of collapsible members and to a surface of the head of the wearer, the flexible inner liner including expansion portions to fill a plurality of voids between the plurality of collapsible members and the head of the wearer.
 21. The method of claim 16, wherein the flexible inner liner is shaped by molding the flexible inner liner to a shape of the inner surfaces of the plurality of collapsible members or rigid outer surface.
 22. The method of claim 16, wherein a first portion and a second portion of the plurality of collapsible members is attached to the inner surface of the outer shell, and the first portion has greater rigidity than the second portion of the plurality of collapsible members.
 23. The method of claim 16, wherein upon permanent deformation of at least one of the plurality of collapsible members, the method further comprises: detaching the flexible inner liner from the inner surfaces of the plurality of collapsible members; detaching a consumed first collapsible member from the inner surface of the rigid outer shell, wherein the consumed first collapsible member is individually detachable relative to the plurality of collapsible members; replacing the consumed first collapsible member with a second collapsible member, the second collapsible member having equivalent shape to the consumed first collapsible member; reattaching the flexible inner liner to the inner surfaces of the plurality of collapsible members.
 24. A method of manufacturing a custom multi-layered helmet, the method comprising: providing a rigid outer shell having an inner surface, the inner surface of the rigid outer shell being attached to a rigid collapsible pad having an inner surface; positioning a moldable liner blank adjacent to the inner surface of the rigid collapsible pad and adjacent to a surface of a head of a wearer, the liner blank contacting the inner surface of the rigid collapsible pad and the surface of the head simultaneously; molding the liner blank to a shape defined by the inner surface of the rigid collapsible pad and the surface of the head; stiffening the liner blank to retain the shape; removably attaching the liner blank to the rigid outer shell or rigid collapsible pad. 